Buoyant materials can be used in boats, submarines, underwater pipelines, and other mechanical structures and vehicles for use with an aquatic environment. Structures that provide buoyancy can be designed with the inspiration of bionics. For example, a king lotus plant has a skeleton structure on its bottom surface composed of many thick veins. A diaphragm connects the veins, increasing the specific area and the volume of the air chamber formed therein. The resulting structure can float on water surface while supporting 30-80 kg of weight.